99mTc-hexamethylpropylene amineoxime leukocyte scintigraphy in acute pancreatitis: an alternative to contrast-enhanced computed tomography?

Comparative analysis of selected scales to assess prognosis in acute pancreatitis

OBJECTIVE

To evaluate the utility of selected scales to prognosticate the severity and risk for death among patients with acute pancreatitis (AP) according to the revised Atlanta classification published in 2012.

METHODS

Prospective data regarding patients hospitalized due to AP were analyzed. The final analysis included a total of 1014 patients. The bedside index for severity in acute pancreatitis (BISAP), Panc 3 scores and Ranson scales were calculated using data from the first 24 h of admission.

RESULTS

Mild AP was diagnosed in 822 (81.1%) cases, moderate in 122 (12%) and severe in 70 (6.9%); 38 (3.7%) patients died. The main causes of AP were cholelithiasis (34%) and alcohol abuse (26.7%). Recurrence of AP was observed in 244 (24.1%) patients. In prognosticating the severity of AP, the most useful scale proved to be the Acute Physiology and Chronic Health Evaluation (APACHE) II (area under the curve [AUC] 0.724 [95% CI 0.655 to 0.793]), followed by BISAP (AUC 0.693 [95% CI 0.622 to 0.763]). In prognosticating a moderate versus mild course of AP, the CT severity index proved to be the most decisive (AUC 0.819 [95% CI 0.767 to 0.871]). Regarding prognosis for death, APACHE II had the highest predictive value (AUC 0.726 [95% CI 0.621 to 0.83]); however, a similar sensitivity was observed using the BISAP scale (AUC 0.707 [95% CI 0.618 to 0.797]).

CONCLUSIONS

Scoring systems used in prognosticating the course of the disease vary with regard to sensitivity and specificity. The CT severity index scoring system showed the highest precision in prognosticating moderately severe AP (as per the revised Atlanta criteria, 2012); however, in prognosticating a severe course of disease and mortality, APACHE II proved to have the greatest predictive value.

PET/CT with 18F-FDG-labeled autologous leukocytes for the diagnosis of infected fluid collections in acute pancreatitis

Early detection of infection in acute pancreatitis (AP) affects the choice of treatment and clinical outcome. We used PET/CT with (18)F-FDG-labeled autologous leukocytes to detect infection in pancreatic or peripancreatic fluid collections in patients with AP.

METHODS

Forty-one patients (28 men and 13 women) who were 21-69 y old (mean ± SD, 41 ± 11.5) and had AP and radiologic evidence of a fluid collection in or around the pancreas were studied. Leukocytes were separated from the patient's venous blood, labeled with (18)F-FDG, and reinjected intravenously; PET/CT images were acquired 2 h later. A final diagnosis of infection was based on microbiologic culture of fluid aspirated from the collection. Patients were treated with supportive care and antibiotics; percutaneous drainage or laparotomy was performed when indicated.

RESULTS

Blood glucose level, total leukocyte count, neutrophil count, and leukocyte labeling efficiency varied from 83 to 212 mg/100 mL (118 ± 30), 4,600 to 24,200/mm(3) (11,648 ± 5,376), 55% to 90% (73 ± 10), and 31% to 97% (81 ± 17), respectively. Increased tracer uptake in the fluid collection was seen in 12 of 41 patients; 10 had culture-proven infection and underwent percutaneous drainage, and aspiration was unsuccessful in 2. The scan results were negative for infection in 29 patients; 25 had fluid culture results that were negative for infection, and aspiration was unsuccessful in 4. The sensitivity, specificity, and accuracy of the scan were all 100% in 35 patients for whom fluid culture reports were available.

CONCLUSION

PET/CT with (18)F-FDG-labeled leukocytes is a noninvasive and reliable method for the diagnosis of infection in pancreatic or peripancreatic fluid collections in patients with AP.

Serum proinflammatory cytokine levels and white blood cell differential count in patients with different degrees of severity of acute alcoholic pancreatitis

Several studies suggest that cytokines and neutrophils play an important role in the pathogenesis of acute pancreatitis (AP). The AIM OF THE STUDY was to assess the systemic release of proinflammatory cytokines and WBC (white blood cells) count with differential in patients with acute alcoholic pancreatitis (AAP) and to characterize the differences between patients with mild and severe forms of the disease.

MATERIAL AND METHODS

Thirty-five patients with the mild form of acute alcoholic pancreatitis (MAAP) were compared to 11 patients with severe acute alcoholic pancreatitis (SAAP). Serum levels of IL-6, IL-8, IL-12p40 and WBC differential count were measured every second day during the first week after admission.

RESULTS

During the course of the study, the average level of IL-6 was significantly (p<0.05) higher in patients with SAAP than in patients with the mild form of the disease (MAAP). Serum levels of IL-8 and IL-12p40 on admission were higher in patients with SAAP than in patients with MAAP but the difference was not statistically significant. Of all the types of WBCs, neutrophils were significantly (p<0.05) elevated the entire time in SAAP patients when compared to patients with MAAP on 5th and 7th day from admission to hospital.

CONCLUSIONS

Patients with SAAP had significantly higher proinflammatory cytokine IL-6 levels and neutrophil counts than patients with MAAP. The results suggest that proliferation and overstimulation of this subset of leukocytes might contribute to the development of the systemic inflammatory response in patients with SAAP.

Contrast-enhanced ultrasound in the staging of acute pancreatitis

OBJECTIVE

To determine the diagnostic value of contrast-enhanced ultrasound (CEUS) in the assessment of acute pancreatitis, with computed tomography (CT) as the reference standard.

METHODS

Fifty consecutive patients (mean age 58.4 years; range 23-86 years) with acute pancreatitis underwent prospectively both CT and ultrasonography, including CEUS, within a 24-h interval. Pancreatic vascularisation was evaluated with CEUS after injection of a second-generation US contrast-enhancing agent. Acute pancreatitis severity was graded according to the Balthazar index. The results were compared with CT severity index and clinical outcome by using Spearman's correlation coefficient.

RESULTS

A significant correlation between CT and CEUS was found for the CT severity index (r = 0.926), extent of necrosis (r = 0.893) and Balthazar grade (r = 0.884). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting severe acute pancreatitis based on CT findings (severity index greater than 3 and/or presence of necrosis) were respectively 91%, 100%, 100% and 83%. A significant correlation between CEUS severity index and clinical variables was found: Ranson score (r = 0.442), C-reactive protein (CRP) levels 48 h after admission (r = 0.385) and length of hospital stay (r = 0.362).

CONCLUSION

CEUS is comparable to CT in detecting pancreatic necrosis as well as predicting its clinical course. Therefore, when CT is contraindicated CEUS may be a valid alternative.

Cancer risk among the relatives of patients with pancreatic ductal adenocarcinoma

BACKGROUND/AIMS

Pancreatic cancer is a leading cause of cancer-related death; the most consistently identified risk factors are smoking and family history. Our aims were to examine familial aggregations of pancreas and other cancers, and to determine the relative risk of the family members.

METHODS

We prospectively collected data on the families of patients presenting with pancreatic ductal adenocarcinoma. Smoking habits and alcohol consumption of the probands were compared with the available statistics on the Italian population. Mortality from cancer was investigated in first-degree relatives, and age-dependent risks of dying from pancreatic cancer and other tumors were compared with background population levels.

RESULTS

Data for 570 families were collected, including 9,204 relatives. Probands were 3- to 5-fold more often heavy smokers than the general population, and 9.3% of them reported a positive family history of pancreatic cancer. In first-degree relatives, only mortality from pancreatic cancer was significantly increased (relative risk at age 85 years = 2.7). Lifetime risk of dying of pancreas cancer was 4.1% for the relatives of all probands, and was 7.2% for the relatives of probands who developed disease before 60 years of age.

CONCLUSIONS

The data suggest that genetic susceptibility to pancreatic cancer may be attributable, in addition to BRCA2, to moderate- to low-penetrance gene(s).

Scintigraphic evaluation of acute pancreatitis patients with 99mTc-HMPAO-labelled leukocytes

OBJECTIVE

To demonstrate the localization of leukocytes in the pancreas during acute pancreatitis and to evaluate the potential use of 99mTc-HMPAO-labelled leukocytes in the diagnostic assessment of patients with acute pancreatitis.

METHODS

The study was performed with 20 patients (11 females, nine males; ranging in age from 26 to 86 years, mean 55 years). Labelled leukocyte scintigraphy using planar imaging was performed on all patients, seven of whom were also examined by single photon emission computed tomography (SPECT). According to Ranson criteria, 10 patients had mild pancreatitis (group A), six had severe pancreatitis (group B) and four had necrotic pancreatitis (group C). Twelve patients had biliary pancreatitis and the other eight patients had no obvious cause.

RESULTS

All patients of group C, four of group B, two of group A had a positive leukocyte scan. The positive leukocyte scintigraphy value for the detection of a lethal course of acute pancreatitis was 100%; of a severe course, 66.7%; and of a mild course, 20%. These findings are statistically significant (P=0.005 in chi-squared tests result). The results of leukocyte scintigraphy compared with those of CT were also statistically significant (P=0.001 in chi-squared tests). All the patients diagnosed with pancreatic necrosis by CT had a positive leukocyte scan, but only three of 13 patients without pancreatic necrosis that could be detected by computed tomography had a positive leukocyte scan.

CONCLUSIONS

There was a significant correlation between the severity of the disease and leukocyte infiltration. Considering these results, we believe that leukocyte infiltration in acute pancreatitis can be demonstrated rapidly and accurately and by noninvasive 99mTc-HMPAO labelled leukocyte scintigraphy.

New advances in pancreatic imaging

PURPOSE OF REVIEW

Exciting new developments and applications of imaging techniques in pancreatic diseases have emerged. This review discusses these new advances and how they are improving our ability to diagnose malignancies and inflammatory lesions, to grade severity of pancreatitis, and to stage pancreatic cancer accurately.

RECENT FINDINGS

A new computed tomography severity index shows promise for grading the severity of acute pancreatitis. Magnetic resonance imaging is comparable with computed tomography in staging acute pancreatitis. Analysis of pancreatograms and textural changes of the parenchyma may prove helpful in diagnosing chronic pancreatitis. Contrast enhanced ultrasonography may prove to be a useful way to judge the degree of inflammation and fibrosis in autoimmune pancreatitis and to monitor response to steroid therapy. The debate over the best means of staging pancreatic cancer has focused on endoscopic ultrasound and computed tomography. Preliminary studies with contrast enhanced ultrasonography report improved diagnostic and staging capabilities with pancreatic cystic and solid neoplasms. Improvements in positron emission tomography/computed tomography scans may improve the detection of neuroendocrine tumors.

SUMMARY

These new advances will help refine the diagnosis and staging of pancreatic diseases.